explain what an inline xattr is and how it relates to omap

The logic of the configuration flags related to xattr is clarified to define what an inline xattr is and when storing in the object map is preferred.

http://tracker.ceph.com/issues/4617 refs #4617

Signed-off-by: Loic Dachary <loic@dachary.org>
mds: trigger tableserver active/recovery hook even for self

The tableserver now sends a READY message to clients when they go active;
we need to do this even for our own local tableclients, or else they do
not initialize and hang on first use after bringing up a fresh cluster.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Merge pull request #184 from dachary/wip-4617

explain what an inline xattr is and how it relates to omap
README: fix dependency lists

1) automake appeared twice
2) make apt-get command match the list
Merge git://github.com/ceph/ceph